A captain is a police rank in some countries, such as the United States and France.
Police captain Wikipedia
France uses the rank of capitaine for management duties in both uniformed and plain-clothed policing. The rank comes senior to lieutenant and junior to commandant.
This rank was previously known as inspecteur principal for plain-clothed officers, and officier de la paix principal for officers in uniform.
In the United Kingdom, the approximate equivalent rank of a police captain is that of chief inspector.
In most U.S. police departments, the rank of captain is immediately above that of lieutenant. A police captain is often the officer in charge of a precinct. In the New York City Police Department, the rank of captain is below deputy inspector. Unlike the military version, where the rank of captain may be held by junior officers with 4 to 11 years of service, police and fire captains are usually veterans with extensive experience. In some smaller U.S. police departments, a person holding the rank of police captain may be in charge of a division (patrol division, detective division, etc.) within that department. In larger police departments however, a police captain may command only one section of a precinct which is commanded by either a police major, police inspector, or the next highest rank. Nevertheless, the rank of police captain is separated from the ranks of police lieutenant and police sergeant. In addition, a police captain is considered upper-level management in most large urban police departments.